Multiple switch inputs

  • Hello all,

    I'm new here and also new to MySensors. I got here trough Domoticz.

    At the moment I have an Arduino Nano running and configured as a serial gateway trough USB.
    I've combined the relay and temperature sketch and now I can use a ds18b20 and 8 relays simultaneous on that board.

    But I want to add some switches too. I've seen a button sketch but that is for just one button.
    I've read about expanding this sketch would give problems with the debounce code.

    Does anyone have an example for multiple switches on one Arduino?

    Thanks in advance!

  • Thanks, it seems the switches also turn on the relays directly?
    I have to figure out the code. I just want to have independent switch inputs.

    If there is some code which has only switches it would help a lot 🙂


  • Just concentrate on the looping over arrays logic, then it's not that hard to break the link between the buttons and the relays. Did this myself here, despite having a lot of other stuff done there maybe this helps 😉

  • @rejoe2 said in Multiple switch inputs:

    Thanks, I will dive into the code then 🙂

  • Well to make three inputs I've come to this using the code you mentioned...
    I've removed the invert function because I could get Domotics invert the
    monitoring. And I've added an initial read at startup. Because at powering-up
    the switches were not read. Any comments? Regards!

    // Enable debug prints to serial monitor
    #define MY_DEBUG
    // Enable serial gateway
    #include <SPI.h>
    #include <MySensors.h>
    #include <Bounce2.h>
    // Define Sensor ID's
    #define KNOB_A_ID 1   // Id of the sensor child
    #define KNOB_B_ID 2   // Id of the sensor child
    #define KNOB_C_ID 3   // Id of the sensor child
    // Define buttons
    const int buttonPinA = 10;
    const int buttonPinB = 11;
    const int buttonPinC = 12;
    // Define Variables
    int oldValueA = 0;
    int oldValueB = 0;
    int oldValueC = 0;
    bool stateA = false;
    bool stateB = false;
    bool stateC = false;
    int trigger = 0;
    Bounce debouncerA = Bounce();
    Bounce debouncerB = Bounce();
    Bounce debouncerC = Bounce();
    MyMessage msgA(KNOB_A_ID, V_STATUS);
    MyMessage msgB(KNOB_B_ID, V_STATUS);
    MyMessage msgC(KNOB_C_ID, V_STATUS);
    void setup()
      pinMode(buttonPinA, INPUT_PULLUP); // Setup the button Activate internal pull-up
      pinMode(buttonPinB, INPUT_PULLUP); // Setup the button Activate internal pull-up
      pinMode(buttonPinC, INPUT_PULLUP); // Setup the button Activate internal pull-up
      // After setting up the buttons, setup debouncer
        /*--------------------- Added these lines for toggle switch-------------------------*/
      oldValueA = digitalRead(buttonPinA);  // set oldValueA to the current status of the toggle switch
      oldValueB = digitalRead(buttonPinB);  // set oldValueB to the current status of the toggle switch
      oldValueC = digitalRead(buttonPinC);  // set oldValueC to the current status of the toggle switch  
    void presentation()  {
      // Send the sketch version information to the gateway and Controller
      sendSketchInfo("2x bistable button", "1.1");
      // Register all sensors to gw (they will be created as child devices)
      present(KNOB_A_ID, S_LIGHT);
      present(KNOB_B_ID, S_LIGHT);
      present(KNOB_C_ID, S_LIGHT);  
    void loop()
      if (trigger == 0)
          debouncerA.update(); // Get the startup valueA
          int valueA =;
          send(msgA.set(valueA==HIGH ? 0 : 1));
          debouncerB.update(); // Get the startup valueB
          int valueB =;
          send(msgB.set(valueB==HIGH ? 0 : 1));
          debouncerC.update(); // Get the startup valueC
          int valueC =;
          send(msgC.set(valueC==HIGH ? 0 : 1));
          trigger = 1;
      // Get the update valueA
      int valueA =;
      if (valueA != oldValueA) {
         // Send in the new valueA
         send(msgA.set(valueA==HIGH ? 0 : 1));
         oldValueA = valueA;
      // Get the update valueB
      int valueB =;
      if (valueB != oldValueB) {
         // Send in the new valueB
         send(msgB.set(valueB==HIGH ? 0 : 1));
         oldValueB = valueB;
      // Get the update valueC
      int valueC =;
      if (valueC != oldValueC) {
         // Send in the new valueC
         send(msgC.set(valueC==HIGH ? 0 : 1));
         oldValueC = valueC;

  • Seems to be a good starting point, but some remarks:

    • Using PINs 10-12 might not be the best choice in case you want to add a radio later (my code was for RS485@HWSerial)
    • Doing this kind of task using arrays gives much more flexibility and easier reading imho

    So essential Part of the sketch could be reduced to something like (untested, changing PINs recommended):

    #include <Bounce2.h>
    #define FIRST_PIR_ID 1
    #define MAX_PIRS 3 
    const uint8_t pirPin[] = {10, 11,12};   //  switch around pins to your desire
    Bounce debouncer[MAX_PIRS];
    MyMessage pirMsg(0, V_TRIPPED);
    bool oldPir[MAX_PIRS] = {false};
    void before()
    void presentation() {
      // Send the sketch version information to the gateway and Controller
      sendSketchInfo(SN, SV);
      // Fetch the number of attached temperature sensors
      for (int i = 0; i < MAX_PIRS; i++) { //i < numSensors &&
        present(FIRST_PIR_ID + i, S_MOTION);
    void setup()
      for (uint8_t i = 0; i < MAX_PIRS; i++) {
        debouncer[i] = Bounce();                        // initialize debouncer
        debouncer[i].attach(pirPin[i], INPUT_PULLUP);
        oldPir[i] =  debouncer[i].read();
    void loop() {
      bool pir[MAX_PIRS];
      for (uint8_t i = 0; i < MAX_PIRS; i++) {
        pir[i] = debouncer[i].read();
        if (pir[i] != oldPir[i]) {
          send(pirMsg.setSensor(FIRST_PIR_ID + i).set( pir[i])); // Send tripped value to gw
          oldPir[i] = pir[i];

  • Thanks for the comment, I will look at it.

    Another question, the inputs look exactly like an output in domoticz.
    I can even switch on the lamp with the mouse. Of course there is nothing happening
    because it is an input. But it is a bit confusing. Is this a Domoticz setting? Or can I change
    something in the MySensors code for this? Thanks!

    0_1532950762825_inputs and outputs.png

  • @pdp8 Despite not beeing familiar with domoticz, this behaviour seems to be logic to me: You presentet a light device, so this typiclly is switchable from controller side.
    You might either change the handling within domiticz or present a different Child Type (my code uses motion).

  • Hmm, I've changed it to S_DOOR now. But I still can turn it on and off in Domoticz.
    I guess this is a Domoticz thing and has nothing to do with MySensors... Weird...

  • it's normal with domoticz same motion you can do it off
    you have to protect how it works you can not operate it anymore

  • @pdp8 By default Domoticz will add a S_BINARY, S_DOOR, S_MOTION and S_DIMMER (and likely a few others) device in the form of a switchable lamp. You can add it to the active devices and then change the type to be a different device.

    For example when you create a S_MOTION device, it initially gets added as a lamp in Domoticz, but then you can later change the switch type to be a motion sensor. This changes the icon displayed in Domoticz and also stops you from changing the state.

  • yes you can change
    you go on switch press edit after a window that opens
    you go to Switch Type and you find motion